The invention relates to an exhaust gas turbocharger for a reciprocating internal combustion engine and to a c reciprocating internal combustion engine including an exhaust gas turbocharger to which exhaust gas is supplied from the internal combustion engine via two separate exhaust ducts.
DE 101 52 804 A1 describes an exhaust gas turbocharger for an internal combustion engine, which comprises an exhaust gas turbine in the exhaust manifold and a compressor in the inlet manifold, the turbine rotor being driven by the pressurized exhaust gases from the internal combustion engine and the rotation of the turbine rotor being transmitted by a shaft to the compressor wheel, which thereupon draws in ambient air and compresses it to a higher boost pressure. The exhaust gas turbine has two exhaust gas flow passages of different sizes, which are each supplied with the exhaust gases from one of two cylinder banks of the internal combustion engine. Owing to the differing sizes of the exhaust gas flow passages, a higher exhaust gas backpressure is created in the exhaust line section of the smaller exhaust gas flow passage than in the exhaust line section via which the larger exhaust gas flow is supplied with exhaust gases. This higher exhaust gas backpressure can be utilized for improved exhaust gas recirculation, which comprises a recirculation line, which branches off from the exhaust gas line section of the smaller exhaust gas flow passage and extends to the inlet manifold. The exhaust gas recirculation improves the exhaust properties, serving in particular to reduce NOx emissions. In addition, exhaust gas recirculation with asymmetrical turbine inlet flow passages leads to favorable fuel consumption.
Based on this state of the art, it is the object of the present invention to further reduce the emissions and fuel consumption of supercharged internal combustion engines. In particular, the efficiency of the exhaust gas turbocharger of an internal combustion engine is to be improved.